Malaysia Airlines Flight MH370 Flight departs at 12:41am (1441 GMT Friday), and is due to land in Beijing at 6:30am (2230 GMT) the same day. On board the Boeing 777-200ER are 227 passengers and 12 crew.

Missing plane last has contact with air traffic controllers 120 nautical miles off the east coast of the Malaysian town of Kota Bharu.

Civil Aviation Authority of Vietnam says plane failed to check in as scheduled at 1721 GMT while flying over sea between Malaysia and Ho Chi Minh City.

Flight tracking website flightaware.com shows plane flew northeast over Malaysia after takeoff and climbed to altitude of 35,000 feet. The flight vanished from website's tracking records a minute later while still climbing.

Malaysia search ships see no sign of wreckage in area where flights last made contact. Vietnam says giant oil slick and column of smoke seen in its waters.

Interpol Secretary General Ronald Noble names the two men who boarded jet with stolen passports as Iranians, aged 18 and 29, who had entered Malaysia using their real passports. "The more information we get, the more we are inclined to conclude it is not a terrorist incident," Noble said.

Malaysian police chief said the younger man appeared to be an illegal immigrant. His mother was waiting for him in Frankfurt and had been in contact with authorities, he said.

Malaysia's military believes missing jet turned and flew hundreds of kilometres to the west after it last made contact with civilian air traffic control off the country's east coast, a senior officer told Reuters. The jet made it into the Strait of Malacca, one of the world's busiest shipping channels, along Malaysia's west coast, said the officer.

A Colorado-based company has put "crowdsourcing" to work in search for a missing jet, enlisting Internet users to comb through satellite images of more than 1,200 square miles (3,200 square km) of open seas for any signs of wreckage.